Dust separator



Feb. l,v 1944. s. HoLM Erm.

DUST SEPARATOR med Jan.. s, 194s 07,. m, m j@ im yam n l m Hl f MN 4 WM "MTM 2 m m .M m Muk/ W .A A v W |.|f v s .P l Z Patented Feel, 1944 UNITED STATES H PATEN DUST sEPARn'roR Sven Holm and Harold F. Keough, Wellsville,

N. Y., assignors to The Air Preheater Corporation, New York, N. Y.

Application January 5, 1943, Serial No. 471,336 4 claims. (ol. 18s- 57) The present` invention relates to dust separators and particularly to an improved movable filtering screen of the type periodically cleansed of dust accumulations.

In carrying out the inventiona filtering screen is disposed in zig-zag arrangement across a gas duct and is of such length that part of it may be retracted at intervals from the gas duct into a chamber at the side of the latter to be cleaned of dust accumulations by subjecting it 'to air jets or the like.. The invention will bebest understood upon consideration of the following detailed description of an illustrative embodiment thereof when read in conjunction with the accompanying drawing in which:

Figure 1 is a diagrammatic elevational view, partly in section, of a, dust separator embodying the present invention;

Figure 2 is a fragmentary sectional View on the line 2-2 in Figure 1 showing part of the operating means for traversing the ltering screen across the gas duct; and- Figure 3 is a fragmentary view on an enlarged scale of part of a carriage and track for supporting the screen for movement across the duct.

In the drawing, the numerals I and II designate two vertically alined sections of a gas duct between which is interposed a dust separating chamber I2 of somewhat greater width than the duct. The opposite side walls I3 and I4 of chamber I2 are formed with alined openings I5, I6, each communicating with a recess or subsidiary chamber II, I 8 at either side of the main chamber I2 into which parts of the filtering screen are alternately drawn for cleaning.

Extending completely across the chamber I2 and into the recesses I'I and I8 at 'either side thereof are several tracks, of which one is shown in Figure 2, on which tracks 20 for guiding a plurality of carriages 2I equipped' with rollers 2Ia for traversing the filtering screen into and out of the cleaning recesses I'I, I8. The filtering screen comprises a plurality of reticulated lter panels 22 of suitable form pivotally connected in pairs at their lower ends 23 and attached at their upper ends to collars 24 rotatably mounted on pins 25 carried by the carriages 2| to form a collapsible or folding screen disposed in zig-zag arrangement across the path of gases flowing throughthe cleaning chamber I2. The last panel 22 at either end 0f the screen is guided at its lower end edges in guides 26 mount-ed on the end walls 2l of the auxiliary chambers Il, I8. Near the middle of the screen adjacent panelsI designated 22A and 22B are connected at their upper ends to a door or closure 30 suspended from a carriage 2IB equipped with rollers 2lb riding on track 20, all as shown at the left of Fig. 1. A chain 3I it attachedtocarriage 2IB for traversing the panels 22 of the lter screen. Any suitable type of motor may be used for operating the chain 3I to traverse the screen panels 22; Fig. 1 shows apneumatic motor 32 having a piston provided with a rack 33 for operating the gearing 34 to drive the shaft on which the chained sprocketsv 35 at the right hand side are fixed. As appears in Fig. 2,"the door 30 is formed with an opening through which the track 20 passes so that the door may be slid along the track. A sealing member 36 is provided on the door tovwipe against the track to minimize seepage of either dust or clean` ing air therethrough.

In operation the dust-laden gases flowing from the duct section I0 into the chamber I2 deposit dust particles on the screen panels 22 and the cleansed air is discharged into the duct section II. At suitable intervals the motor 32 is placed in operation and acts through the chain 3l and the carriage 2 IB to move the door 30 from the left hand side of the chamber I2, for example, to the right hand side until it covers the opening I6 to the auxiliary chamber I8. In this movement of the door 30 the screen panels 22 which had been located in the path of the gases are moved into the chamber I8 at the right hand side Where the dust may be blown from the screen by compressed air admitted to pipe 40 which has a plurality of nozzle apertures directed downwardly to project jets of air against the screen panels and cause the dust thereon to be removed and discharged through-the outlet 4I. The initiation and termination of operation of motor 22 to effect the carriage movements as well as the starting and cutting oi of the air jet may be controlled by a suitable timing device.

At the same time that the lter panels 22 which had been exposed to the dust-laden gases are moved into the chamber I8 at the right hand side of the duct, the sections of the screen which was previously located behind door 30 Within chamber I 'I are withdrawn so that a number ofthe panels 22 move with the door I5 and are extended to become disposed in the main chamber I2 in the path of dust-laden gases. Thus certain of the filter panels are exposed to the dust-laden gases for a period and then moved out of the main chambers into one of the cleaning chamber I8 to have the dust purged therefrom While their place in the main chamber I2 is taken by other filter panels moved into place fromA the subsidiary chamber I1 at the opposite side of the dust, this sequence of operation continuing indefinitely. When panels which are laden with dust are moved into one or the other of the subsidiary chambers I'I or I8, the door 30 'cuts off communication between the main chamber I2 and the chamber into which the dirty panels are located and thus seals `A corollary of this feature is that because the openings I 5. Il, respectively, the filter panels 22 located in the subsidiary chamber Il which at any particular time is open to the main chamber l2` are also available for filtering dust from the gases. Consequently a somewhatlarger amount of nltering surface is utilized than would be the case if onlythe width of the duct of the main chamber I2 in alignment with the duct were available for accommodating the active nlter panels.

What we claim is:

l. In a dust separator; a main chamber interposed in a duct through which dust-laden gases flow and having vertical side walls that. define opposite sides of said chamber formed with alined openings; means forming auxiliary chambers at opposite sides of said main chamber in communication with the interior thereof through said openings; a guide track extending across said main chamber and into the auxiliary chamber at either side thereof; a' lter screen disposed transversely of the main chamber in a plurality of zig-zag folds in the path of gases passing through said chamber, said screen being of such length that a plurality of folds are disposed in each of said auxiliary chambers while the remaining folds are disposed across the path of the gases in the main chamber; carriages 'mounted on said track, means for supporting said screen on said carriages; means for moving said carriages to withdraw folds of the screen that are disposed across the main chamber into an auxiliary chamber at one side thereof While at the same time withdrawing a plurality of screen folds from the other auxiliary chamber and disposing them in the path of gases flowing through the latter; and pneumatic means in each auxiliary chamber for removing dust from the parts of the screen disposed therein.

2. In a dust separator; a main chamber interposed in a duct through which dust-laden gases iiow and having vertical side walls that define opposite sides of said chamber' formed with alined openings; means forming auxiliary chambers at opposite sides of saidmain chamber in communication with the interior thereof through said openings; a guide track extending across said main chamber and into the auxiliary chamber at either side fthereof; a filter screen disposed transversely of the main chamber in a plurality of zig-zag folds in the path of gases passing through said chamber, said screen being of such length that aplurality of folds are disposed in each of said auxiliary chamberswhile the remaining folds are disposed across the path of the gases in the main chamber; carriages mounted on said track, means for supporting said screen on said carriages; means for moving said carriages to withdraw folds of the screen that are disposed across the main chamber into an auxiliary chamber at'one side thereof. While at the same timewithdrawing a plurality of screen folds from the other auxiliary chamber and disposing them in the path of gases flowing through the latter; pneumatic means in each auxiliary chamber for removing dust fromthe parts of the screen disposed therein; and means for closing the opening leading from said main chamber into one of said auxiliary chambers upon retraction of dust-laden screen parts into the latter. r

3. In a dust separator; a main chamber interposea in a duct thrown-which cust-laden gases now and having vertical side walls that define opposite sides of said chamber formed with alined openings; means forming auxiliary chambers at opposite sides of said main chamber in communication with the interior thereof through said carriages to withdraw folds of the screen that are disposed across the main chamber into an auxiliary chamber at one side thereof while at the same timefwithdrawing a plurality of screen folds from the other auxiliary chamber and disposing them in the path of gases flowing through the latter; pneumatic means in each auxiliary chamberfor removing dust from the parts of the screen disposed therein; and closure means movable with said screen to cover the opening between said main chamber and the auxiliary chamber into which dust-laden screen folds are retracted.

4. In a dust separator; a main chamber interposed in a duct through which dust-laden gases flow and having vertical side walls that define opposite sides of said chamber formed with alined openings; means forming auxiliary chambers at opposite sides of said main chamber in communication with the interior thereof through said openings; a guide track extending across said main chamber and into the auxiliary chamber at either side thereof a filter screen disposed transversely of the main chamber in a plurality of zig-zag folds in the path of gases passing through said chamber, said screen being of such length that a plurality of folds are disposed in each ofv said auxiliary chambers while the remaining folds are disposed across the path of the gases in themain chamber; carriages mounted on said track, means for supporting said screen on said carriages; means for moving said carriages to withdraw folds 0f the screen that are disposed across the main chamber into an auxiliary chamber at one side thereof While at the same time withdrawing a plurality o1 screen folds from the ,other auxiliary chamber and disposing them in the path of gases flowing through the latter; pneumatic means in each auxiliary chamber for removing dust from the parts of the screen disposed therein; and closure means movable back and forth across the main chamber withsaid screen for closing one or the other of the openings leading from said main chamber into said auxiliary chamber to prevent communication between the latter and said main chamber while permitting gases from the main chamber to enter the other auxiliary chamber through the opening communicating there 

